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Finished PersistenceManager

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Signed-off-by: Jim Martens <github@2martens.de>
This commit is contained in:
Jim Martens
2017-05-24 15:07:33 +02:00
parent 90d537f64d
commit 364ecae424
1 changed files with 28 additions and 6 deletions
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34
04/src/PersistenceManager.java
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@ -53,6 +53,7 @@ public class PersistenceManager {
*/
public int beginTransaction() {
_transactions.put(_nextTransactionNumber, false);
logSimple(_nextTransactionNumber, "BOT");
// return the next transaction number and increase it by one afterwards
return _nextTransactionNumber++;
}
@ -70,6 +71,7 @@ public class PersistenceManager {
// only perform commit actions if transaction isn't commited yet
if (!_transactions.get(taid)) {
_transactions.replace(taid, true);
logSimple(taid, "COMMIT");
}
}
@ -95,14 +97,14 @@ public class PersistenceManager {
_transactionPageBuffer.put(taid, pageIDs);
_pageBuffer.put(pageid, data);
// log changes
int lsn = log(taid, pageid, data);
int lsn = logWrite(taid, pageid, data);
_pageLSN.put(pageid, lsn);
// call persist
persist();
}
/**
* Logs the necessary information to the log file.
* Logs a write to the log file.
*
* @param taid
* affected transaction
@ -112,11 +114,32 @@ public class PersistenceManager {
* written data
* @return log sequence number
*/
private int log(int taid, int pageid, String data) {
private int logWrite(int taid, int pageid, String data) {
try {
FileWriter fw = new FileWriter("../data/log.txt", true);
// TODO properly create redo data
fw.write("" + _nextLogSequenceNumber + "," + taid + "," + pageid + "," + data);
fw.write("" + _nextLogSequenceNumber + "," + taid + ",WRITE," + pageid + "," + data);
fw.write("\n");
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
return _nextLogSequenceNumber++;
}
/**
* Logs a BOT to the log file.
*
* @param taid
* affected transaction
* @param type
* log type
* @return log sequence number
*/
private int logSimple(int taid, String type) {
try {
FileWriter fw = new FileWriter("../data/log.txt", true);
fw.write("" + _nextLogSequenceNumber + "," + taid + "," + type + "\n");
fw.write("\n");
fw.close();
} catch (IOException e) {
@ -144,7 +167,6 @@ public class PersistenceManager {
}
}
// TODO update log file as needed
for (int taid : commitedTransactions) {
Set<Integer> pageIDs = _transactionPageBuffer.get(taid);
for (int pageid : pageIDs) {